The present invention refers to a heat pump arrangement for heating purposes comprising a vaporizer designed as a heat exchanger, a compressor for compression of a vaporized medium and a condensor incorporated in a heat distribution system, at which the vaporizer is designed as an icing machine arranged to produce ice slush, and the heat generated during the ice formation is emitted to the vaporizer.
There are nowadays strong attempts to economize on energy sources in all ways. For heating purposes solar energy and heat pump technique are therefore two alternative solutions, which become more and more intersesting but which also have their limitations.
For heating purposes solar energy is collected with solar energy collectors, from which the heat is transferred by means of e.g. air or water. Solar energy collectors can only collect a part of the solar energy which is radiated towards it. The efficiency can be about 50%, but depends strongly on a plurality of factors, e.g. the over-temperature of the collector in relation to the air temperature. The efficiency decreases with a rising over-temperature and vice versa. Another problem when utilizing solar energy for heating purposes is that the intensity of the sun is highest during the summer and lowest during the winter and thus inversely related to the heating demands. For this reason some kind of heat accumulator and/or alternative energy sources must be installed in the system.
In some plants they have tried to supply the heating requirements only with the collected solar energy. In this case it is necessary to work with relatively high temperatures on the collectors, and energy must be stored from the summer to the winter. Owing to the high temperatures the efficiency of the collector is considerably decreased, which means that collectors with very large surface areas must be used. Such a plant also needs a big accumulator volume, i.e. due to the fact that the temperaure only can vary between narrow limits (about +95.degree. C. when fully loaded to about +45.degree. C. when the accumulator is unloaded). There have also been attempts to use salt solutions of different kind in order to increase the stored energy per unit of volume and by that decrease the accumulated volume.
In order to decrease the accumulated volume and temporarily increase the efficiency of the collectors, solar energy collectors are sometimes combined with a heat pump. The vaporizer of the heat pump takes heat from the solar energy collector/accumulator system and delivers heat at a higher temperature by means of the condensor to the heat system. By this combination the temperature variation of the accumulator can increase and its volume can be reduced. However the surface areas of the collectors, as the accumulator volume, are still very large if the entire annual heat requirements of a building shall be supplied in this way.
In many cases attempts have been made to supply the heat requirements only by means of heat pumps without solar energy collectors and accumulators. The heat pump then has to take heat from the air or from the ground. The efficiency or heat factor of the heat pump decreases strongly when the temperature of the primary heat source--in this case the outdoor air or the ground--is low, and is therefore especially unfavorable during cold periods when the heat requirement are highest. The heat pump working with heat from the ground further have the disadvantages that it can be used only for special ground conditions, it has to be placed on a large depth and a large surface of the heat absorbing tube coils is required.